Means for wrapping filaments around tubes or cylinders



MEANS FOR WRAPPING FILAMENTS AROUND TUBES OR CYLINDERS April 20, 1943. w. BRIDGES MENS FOR WRAPPING FILAMENTS AROUND TUBES OR lGYLINDERS 2 Sheets-Sheety 2 Filed March 2. 194.2.

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Patented Apr. 20, 1943 MEANS FOR WRAPPING FILAMENTS AROUND TUBES OR CYLINDERS Walter Bridges, Chelsea, London, England Application March 2, 1942, Serial No. 433,097 In Great Britain October 6, 1941 6 Claims.

{3o-pending patent application No. 410,934 describes apparatus for winding a filament on to a rotatable body, which apparatus is defined herein as comprising a rotatable drum, a brake associated therewith, a brake lever movable to vary the braking effort, a downwardly biased pulley lever associated with the br-ake lever to move it, and a jockey pulley connected to the pulley lever, the arrangement being such that the filament on its way from a supply thereof to the body to be wound passes around the drum and under the jockey pulley, whereby variation in filament tension causes the jockey pulley to rise or fall and the brake lever to rock to vary the braking effort in such manner as to counteract said tension variation. The present invention comprises an improvement in or modification of the apparatus forming the subject-matter of co-pending application No. 410,934 as above defined, which improvement or modification comprises a cam on one of the two levers and a cam follower on the other lever, which cam is so shaped that equal. movements of the pulley lever at different stages in its range of movement result in different movements of the brake lever. The cam is preferably but not necessarily provided on the brake lever.

The improvement or modification provided by the present invention is illustrated in the accom-l panying drawings, in which Figure 1 is an elevation of the relevant parts of a machine for wrapping a filament around a tube or cylinder according to the aforesaid patent application but incorporating the present improvement or modification.

Fig. la is a view in elevation of the remaining portion of the winding machine shown in Fig. 1

Figure 2 is a part sectional elevation of certain parts thereof on a larger scale.

Referring to the speciiication and drawings of the parent application, the machine is in the nature of a lathe having a bed I along which a saddle 2 and tool rest 3 are movable by means of a lead screw and by means of a hand wheel as isi customary in lathes. The cylinder 1 to be wound is supported between the headstock and the toolf stock and is driven from the former. The saddle 2 carries a superstructure i5 on which a wound supply 24 of the winding wire 25 is rotatably mounted. From this supply 24 the wire 25 passes completely around the drum 39 of a band The pulley lever 41 also carries a i to be tightened or released and the braking effort varied. It will be appreciated that as the filament tension uctuates the pulley lever 41 will rise and fall and these movements are communicated to the brake lever 54 in such manner that the braking effort is varied to counteract the tendency to fluctuate. These parts are illustrated in the accompanying drawings. In the parent application, however, the movements of the pulley lever 41 are communicated to the brake lever 54 by means of a pin 53 projecting from the lever 41 and having contact with one inclined edge of the brake lever 54. In the improvement or modification Aforming the subject of the present invention movements of the pulley lever 41 are communicated to the brake lever 54 by means of a cam 1l and follower 58'. A plate cam 1! is adjustably secured to the brake lever 54 in such manner that it may be adjusted towards and away from the jockey pulley 40. To this end the said cam 1I is conveniently provided with a substantially'horizontal slot 12 through which securing bolts or the like 13 extend into the brake lever 41. The cam follower 58 is adjustably secured to the pulley lever, which cam follower may consist of a pin or roller; the adjustment thereof is conveniently provided by a slot 14 extending lengthwise of the pulley lever. This follower 58' makes Contact with that edge of the cam 1I which is presented towards the jockey pulley 4!! and the said edge is suitably shaped such that as the pulley lever 41 descends the movement imparted to the brake lever 54 increases. To this end the upper portion of the said edge is substantially vertical but the lower portion is curved away from the jockey pulley. Therefore small fluctuations in tension resulting in small movements of the pulley lever 41 produce only small movements of the brake lever 54 and small variations in the braking effort. On the other hand, if the tension drops considerably so that the brake lever 41 falls through a substantial angle, the cam follower 58 travels on to the lower curved part of the cam 1i and the brake lever 54 rocks through a considerable angle and a substantial increase in the braking effort is produced.

The brake lever 54 is biased, in the brakeapplying direction, to maintain the cam in contact with the cam follower. In the parent application the said lever is biased by means of a spring. According to the present improvement or modification the necessary bias is provided by a weight 15. The said weight 15 may be attached to an arm 16 projecting from the rear `of the brake lever.

According to another feature of this invention a buffer is provided for resiliently snubbing the upward movement of the pulley lever 41 should the said lever rise above a predetermined attitude. To this end a vertical spindle 11 is slid.

It will be appreciated that when the wire is being pulled off the drum 24 during the winding operation the tension on the wire is greater than when the winding operation is not in progress.V In utilising the tensioning device described in the parent specification it is found that if such device is set to function satisfactorily during the winding operation the weight 5I drops immediately theA winding operation ceases and the brake 36, 39 does not function to arrest such drop; hence when the winding operation is reconnnended there is a length of slack wire which must be re-wound on to the drum 24 and there is a danger that the first coil of wire wound on to the cylinder 1 will not be under the requisite tension. By the present invention these objections are obviated or minimised. It is true that with the improved construction the weight 5l drops when the winding operation is discontinued but by virtue of the cam 1| and cam follower 58 an increased braking effort is applied to arrest such drop. Furthermore when the winding operation is recommenced the aforesaid mushroom head 19 arrests the upward movement of the pulley lever 41 and thereby'prevents or inhibits bounce which in the previous construction tended to produce variation in the wire tension during the initial stages of the winding process.

' I claim:

1; Apparatus for winding a filament drawn from a supply thereof on to a rotatable body comprising a rotatable drum, a brake associated therewith, a brake lever movable to vary the braking effort, a downwardly biased pulley lever associated with the brake lever to move it, a jockey pulley connected to the pulley lever, a cam on one of the two said levers, and a cam i follower on the other lever, wherein the filament on its way from the supply to the body to be wound passes round the drum and under the jockey pulley so that variation in filament tension causes the pulley to rise and fall and the brake lever to rock to vary the braking effort.

2. In apparatus, for winding a lament drawn from a supply thereof on to a rotatable body, comprising a rotatable drum, a brake associated therewith, a brake lever movable to vary the braking effort, a downwardly biased pulley lever, capable of rising and falling, associated with the brake lever to move the latter, and a jockey pulley connected to the pulley lever, the arrangement being such that the filament on its way from the supply to the body passes round the drum and under the pulley so that Variation in filament tension causes the jockey pulley to rise and fall and the brake lever to rock to vary the braking effort in such manner as to counteract said tension variation; the combination of a cam follower on one of said levers and a cam on the other, which cam has a profile, for engagement by the follower, so shaped that equal movements of the pulley lever at different stages in its range of movement result in different movements of the brake lever.

3. In apparatus, for winding afilament drawn from a supply thereof on to a rotatable body, comprising a rotatable drum, a brake associated therewith, a brake lever movable to vary the braking effort, a downwardly biased pulley lever,

capable of rising and falling, associated with the brake lever to move the latter, and a jockey pulley connected to the pulley lever, the ar-V rangement being such that the filament on its way from the supply to the body passes round the drum and under the pulley so that variation in filament tension causes the jockey pulley to rise and fall and the brake lever to rock to vary the braking effort in such manner as to counteract said tension variation; the combination of a cam follower on one of said levers and a cam on the other, which cam has a profile, for engagement'by the follower, shaped Vfor producing increasing movements of the brake lever in the lower stages of the descent of the pulley lever.

4. In apparatus, for winding a filament drawn from a supply thereof on to a rotatable body, comprising a rotatable drum, a brake associated therewith, a brake lever movable to vary the braking effort, a downwardly biased pulley lever, capable of rising and falling, associated with the brake lever to move the latter, and a jockey pulley connected to the pulley lever, the arrangement being such that the filament on its way from the supply to the body passes round the drum and under the pulley so that variation in filament tension causes the jockey pulley to rise and fall and the brake lever to rock to vary the braking effort in such manner as to counteract said tension variation; the combination ofl a cam folower on one of said levers and a cam on the other, which cam has a prole, for engagement by the follower, so shaped that equal move'-V ments of the pulley lever at different stages in its range of movement result in different movements of the brake lever, and a buffer for resiliently snubbing excessive upward movement of the pulley lever. Y Y

5. In apparatus, for winding a filament drawn from a supply thereof on to a rotatable body, comprising a rotatable drum, a brake associated therewith, a brake lever movable to vary the braking effort, a downwardly biased pulley lever, capable of rising and falling, associated with the brake lever to move the latter, and a jockey pulley connected to the pulley lever, the arrangement being such that the filament on its way from the supply to the body passes round the drum and under the pulley so that variation in filament tension causes the jockey pulley to rise and fall and the brake lever to rock to vary the braking effort in such manner as to counter-` act said tension variation; the combination of a camfollower on one of said levers and a cam on the other, which cam has a profile, for engagement by the follower, affording increasing increments of movement of the brake lever for 1equal increments in the descent of the pulley ever.

6. Apparatus according to claim 1, having means for resiliently snubbing the upward movement of the pulley lever above a predetermined attitude.

WALTER BRIDGES. 

